Chafe or fire sleeve for hose

Abstract

A chafe or fire sleeve for a hose is an integral coaxial structure having an inner layer of silicone and an outer layer of urethane in the range of 80%-20% urethane and 20%-80% silicone, respectively. The inner hose structure preferably comprises an elastomeric hose covered by braid, with the silicone bonded onto the braid.

We claim: 
     
       1. A chafe or fire sleeve for an aircraft fuel hose comprising an internal tube with an outer sleeve integrally formed thereon, said sleeve having a pair of coaxial layers, an outer of said coaxial layers being the chafe or fire sleeve made from a mixture of urethane and silicone elastomers, said urethane and silicone in said outer layer being mixed, with their proportions being in the range of 80% to 20% urethane and 20% to 80% silicone, respectively, and an inner of said coaxial layers being silicone. 
     
     
       2. The chafe or fire sleeve of claim 1 wherein the proportions of said urethane and silicone are respectively approximately 70%/30%, and the cure time and temperature are five minutes at 350° F. 
     
     
       3. The chafe or fire sleeve of claim 1 wherein the sleeve is extruded onto said hose. 
     
     
       4. The chafe or fire sleeve of claim 2 wherein the composition of said outer layer is:   ______________________________________                                    
Material           Composition                                            
______________________________________                                    
Urethane           53%                                                    
Silicone           23%                                                    
Silica             5%                                                     
Treated Clay       8%                                                     
Dessicant          2%                                                     
Leveler            2%                                                     
Plasticizer        2%                                                     
Catalyst           1%                                                     
Pigment            3%                                                     
Minor Ingredients  1%                                                     
                   100%                                                   
______________________________________                                    
     
     
     
       5. The chafe or fire sleeve of claim 1 wherein said urethane and silicone are respectively approximately 50%/50%, and the cure time and temperature are five minutes at 350° F. 
     
     
       6. The chafe or fire sleeve of claim 5 wherein the composition of the outer layer is :   ______________________________________                                    
Material           Composition                                            
______________________________________                                    
Urethane           38%                                                    
Silicone           38%                                                    
Silica             5%                                                     
Treated Clay       7%                                                     
Dessicant          2%                                                     
Leveler            2%                                                     
Plasticizer        2%                                                     
Catalyst           2%                                                     
Pigment            3%                                                     
Minor Ingredients  1%                                                     
                   100%                                                   
______________________________________                                    
     
     
     
       7. The chafe or fire sleeve of claim 1 wherein said urethane and silicone are respectively approximately 35%/65%, and the cure time and temperature are ten minutes at 325° F. 
     
     
       8. The chafe or fire sleeve of claim 7 wherein the composition of said outer layer is:   ______________________________________                                    
Material           Composition                                            
______________________________________                                    
Urethane           28%                                                    
Silicone           52%                                                    
Silica              3%                                                    
Treated Clay        4%                                                    
CoAgent             1%                                                    
Dessicant          2.5%                                                   
Leveler            2.5%                                                   
Plasticizer         2%                                                    
Catalyst            1%                                                    
Pigment             3%                                                    
Minor Ingredients   1%                                                    
                   100%                                                   
______________________________________                                    
     
     
     
       9. The chafe or fire sleeve of claim 1 and a hose structure comprising an inner tube made of an elastomeric material covered with braid, said inner layer of silicone being bonded directly onto said braid. 
     
     
       10. The chafe or fire sleeve of claim 9 wherein said braid includes at least some metallic material. 
     
     
       11. The chafe or fire sleeve of claim 1 wherein said outer layer of urethane and silicone mixture is one color and said inner layer of silicone is another color, whereby a chafing of the outer layer of said sleeve is indicated by the color of an inner layer being exposed through the color of the outer layer. 
     
     
       12. A hose comprising an inner tube structure covered by a chafe or fire sleeve coaxially formed thereon, said chafe or fire sleeve being a coaxial member comprising an outer layer of urethane and silicone elastomers mixed in the range of, respectively, 80%/20% to 20%/80%, and the inner member being a layer of silicone formed between said inner tube and said outer layer. 
     
     
       13. The hose of claim 12 wherein said inner tube structure includes an elastomeric hose covered by a braid, and said coaxial member comprises an inner layer of silicone bonded to said braid. 
     
     
       14. The hose of claim 13 wherein said braid includes a layer of metallic material. 
     
     
       15. The hose of claim 13 wherein said braid includes a layer of reinforcing material. 
     
     
       16. The hose of claim 12 wherein said sleeve is extruded onto said inner tube.